﻿/*
  KeePass Password Safe - The Open-Source Password Manager
  Copyright (C) 2003-2017 Dominik Reichl <dominik.reichl@t-online.de>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

using KeePassLib.Utility;

namespace KeePassLib.Serialization
{
  public sealed class BinaryReaderEx
  {
    private Stream m_s;
    // private Encoding m_enc; // See constructor

    private string m_strReadExcp; // May be null
    public string ReadExceptionText
    {
      get { return m_strReadExcp; }
      set { m_strReadExcp = value; }
    }

    private Stream m_sCopyTo = null;
    /// <summary>
    /// If this property is set to a non-null stream, all data that
    /// is read from the input stream is automatically written to
    /// the copy stream (before returning the read data).
    /// </summary>
    public Stream CopyDataTo
    {
      get { return m_sCopyTo; }
      set { m_sCopyTo = value; }
    }

    public BinaryReaderEx(Stream input, Encoding encoding,
        string strReadExceptionText)
    {
      if (input == null) throw new ArgumentNullException("input");

      m_s = input;
      // m_enc = encoding; // Not used yet
      m_strReadExcp = strReadExceptionText;
    }

    public byte[] ReadBytes(int nCount)
    {
      try
      {
        byte[] pb = MemUtil.Read(m_s, nCount);
        if ((pb == null) || (pb.Length != nCount))
        {
          if (!string.IsNullOrEmpty(m_strReadExcp))
            throw new EndOfStreamException(m_strReadExcp);
          else throw new EndOfStreamException();
        }

        if (m_sCopyTo != null) m_sCopyTo.Write(pb, 0, pb.Length);
        return pb;
      }
      catch (Exception)
      {
        if (!string.IsNullOrEmpty(m_strReadExcp))
          throw new IOException(m_strReadExcp);
        else throw;
      }
    }

    public byte ReadByte()
    {
      byte[] pb = ReadBytes(1);
      return pb[0];
    }
  }
}
